Men who play violent video games and are asked to think about them for a day exhibit greater aggression 24 hours later than: 1, men who play violent video games but don't think about them; 2, men who play nonviolent video games; and 3, women, even if they play violent video games, and even if they then think about those violent video games.

There is a certain "duh" factor involved in these findings, which were recently published in the journal Social Psychological and Personality Science, but the researchers proceeded to title their paper, "Violent Video Games Cause an Increase in Aggression Long After the Game Has Been Turned Off." Not to get bogged down in questions of time and relativity, but is 24 hours really "long after"?

Here's how the study worked. The researchers, in the hopes of determining whether violent video games have a 24-hour rumination effect, randomly assigned college students one of six video games for 20 minutes, half the games being violent (such as Mortal Kombat) and half being nonviolent (such as Guitar Hero).

Half the players were then told to, over "the next 24 hours, think about your play of the game and try to identify ways your game play could improve when you play again."

All participants returned 24 hours later to have their aggression levels tested. Aggression was measured, as Ohio State University professor of communications and psychology Brad Bushman explained to me by e-mail, as follows:

Participants competed with an ostensible partner in which the winner could punish the loser with loud blasts of noise delivered through headphones. The noise levels ranged from 0 to 105 decibels (about the same level as a fire alarm). The winner could also determine how long the loser suffered by controlling the noise duration.

Yikes. The researchers found that the men who played violent video games but did not think about them tested no more aggressively than those who did not play violent video games at all, while the men who both played and ruminated exhibited the highest levels of aggression.

The researchers also found that women who both played and thought about violent video games did not exhibit increased aggression the following day.

Whether violent video games have a compound effect (more minutes of play = greater aggression?) or a longer effect (does the aggression last longer than 24 hours, and if so, how much longer?) may soon be the questions forming future studies. In the meantime, if someone is complaining about all the violent video games you've been spending your time on, you can always assure them you're at least not ruminating.